Quatermass II (1955)

Professor Quatermass is trying to perfect a dangerously unstable nuclear-powered rocket engine. After a disastrous test firing in Australia, his soon-to-be son-in-law, Captain John Dillon, draws the Professor's attention to a strange hollow meteorite which interrupted an Army Training exercise. Quatermass and Dillon investigate, and discover a vast government production plant which has some connection with the meteorites. After coming in contact with the noxious gas contained inside the meteorites, Dillon is taken away by the plant's security guards. When Quatermass presses this issue with an old civil service acquaintance, he learns that the plant is supposedly making synthetic food. Both men learn that this is untrue, and that the true products of the plant will threaten the world itself.